Mar.4 (GMM) Takuma Sato on Wednesday insisted he is not set to become Red Bull's formula one reserve driver in 2009.

The Japanese tested for Toro Rosso this winter but lost out in the battle for a race seat to French incumbent Sebastien Bourdais.

However, talks with Dietrich Mateschitz's outfit continued, leading to speculation he might land the third driver role for both STR and senior team Red Bull Racing and travel to the Barcelona test next week.

But on Wednesday, the 32-year-old revealed he is "disappointed" an agreement with the energy drinks company could not be reached.

"I am no longer in negotiation with the Toro Rosso or Red Bull teams about their third driver positions," the veteran of 93 grands prix confirmed.